content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  package io.reactivex.flowable.internal.operators;
  
  import java.util.List;
  import java.util.concurrent.*;
  
  import org.reactivestreams.*;
  
  import io.reactivex.common.*;
  import io.reactivex.common.functions.*;
  import io.reactivex.common.internal.functions.*;
  import io.reactivex.flowable.*;
  
  /**
   * Helper utility class to support Flowable with inner classes.
   */
  public final class FlowableInternalHelper {
  
      /** Utility class. */
      private FlowableInternalHelper() {
          throw new IllegalStateException("No instances!");
      }
  
      static final class SimpleGenerator<T, S> implements BiFunction<S, Emitter<T>, S> {
          final Consumer<Emitter<T>> consumer;
  
          SimpleGenerator(Consumer<Emitter<T>> consumer) {
              this.consumer = consumer;
          }
  
          @Override
          public S apply(S t1, Emitter<T> t2) throws Exception {
              consumer.accept(t2);
              return t1;
          }
      }
  
      public static <T, S> BiFunction<S, Emitter<T>, S> simpleGenerator(Consumer<Emitter<T>> consumer) {
          return new SimpleGenerator<T, S>(consumer);
      }
  
      static final class SimpleBiGenerator<T, S> implements BiFunction<S, Emitter<T>, S> {
          final BiConsumer<S, Emitter<T>> consumer;
  
          SimpleBiGenerator(BiConsumer<S, Emitter<T>> consumer) {
              this.consumer = consumer;
          }
  
          @Override
          public S apply(S t1, Emitter<T> t2) throws Exception {
              consumer.accept(t1, t2);
              return t1;
          }
      }
  
      public static <T, S> BiFunction<S, Emitter<T>, S> simpleBiGenerator(BiConsumer<S, Emitter<T>> consumer) {
          return new SimpleBiGenerator<T, S>(consumer);
      }
  
      static final class ItemDelayFunction<T, U> implements Function<T, Publisher<T>> {
          final Function<? super T, ? extends Publisher<U>> itemDelay;
  
          ItemDelayFunction(Function<? super T, ? extends Publisher<U>> itemDelay) {
              this.itemDelay = itemDelay;
          }
  
          @Override
          public Publisher<T> apply(final T v) throws Exception {
              Publisher<U> p = ObjectHelper.requireNonNull(itemDelay.apply(v), "The itemDelay returned a null Publisher");
              return new FlowableTakePublisher<U>(p, 1).map(Functions.justFunction(v)).defaultIfEmpty(v);
          }
      }
  
      public static <T, U> Function<T, Publisher<T>> itemDelay(final Function<? super T, ? extends Publisher<U>> itemDelay) {
          return new ItemDelayFunction<T, U>(itemDelay);
      }
  
      static final class SubscriberOnNext<T> implements Consumer<T> {
          final Subscriber<T> subscriber;
  
          SubscriberOnNext(Subscriber<T> subscriber) {
              this.subscriber = subscriber;
          }
  
          @Override
          public void accept(T v) throws Exception {
              subscriber.onNext(v);
          }
      }
  
      static final class SubscriberOnError<T> implements Consumer<Throwable> {
          final Subscriber<T> subscriber;
  
          SubscriberOnError(Subscriber<T> subscriber) {
              this.subscriber = subscriber;
          }
  
          @Override
          public void accept(Throwable v) throws Exception {
              subscriber.onError(v);
          }
      }
  
      static final class SubscriberOnComplete<T> implements Action {
          final Subscriber<T> subscriber;
  
          SubscriberOnComplete(Subscriber<T> subscriber) {
              this.subscriber = subscriber;
          }
  
          @Override
          public void run() throws Exception {
              subscriber.onComplete();
          }
      }
  
      public static <T> Consumer<T> subscriberOnNext(Subscriber<T> subscriber) {
          return new SubscriberOnNext<T>(subscriber);
      }
  
      public static <T> Consumer<Throwable> subscriberOnError(Subscriber<T> subscriber) {
          return new SubscriberOnError<T>(subscriber);
      }
  
      public static <T> Action subscriberOnComplete(Subscriber<T> subscriber) {
          return new SubscriberOnComplete<T>(subscriber);
      }
  
      static final class FlatMapWithCombinerInner<U, R, T> implements Function<U, R> {
          private final BiFunction<? super T, ? super U, ? extends R> combiner;
          private final T t;
  
          FlatMapWithCombinerInner(BiFunction<? super T, ? super U, ? extends R> combiner, T t) {
              this.combiner = combiner;
              this.t = t;
          }
  
          @Override
          public R apply(U w) throws Exception {
              return combiner.apply(t, w);
          }
      }
  
      static final class FlatMapWithCombinerOuter<T, R, U> implements Function<T, Publisher<R>> {
          private final BiFunction<? super T, ? super U, ? extends R> combiner;
          private final Function<? super T, ? extends Publisher<? extends U>> mapper;
  
          FlatMapWithCombinerOuter(BiFunction<? super T, ? super U, ? extends R> combiner,
                  Function<? super T, ? extends Publisher<? extends U>> mapper) {
              this.combiner = combiner;
              this.mapper = mapper;
          }
  
          @Override
          public Publisher<R> apply(final T t) throws Exception {
              @SuppressWarnings("unchecked")
              Publisher<U> u = (Publisher<U>)ObjectHelper.requireNonNull(mapper.apply(t), "The mapper returned a null Publisher");
              return new FlowableMapPublisher<U, R>(u, new FlatMapWithCombinerInner<U, R, T>(combiner, t));
          }
      }
  
      public static <T, U, R> Function<T, Publisher<R>> flatMapWithCombiner(
              final Function<? super T, ? extends Publisher<? extends U>> mapper,
                      final BiFunction<? super T, ? super U, ? extends R> combiner) {
          return new FlatMapWithCombinerOuter<T, R, U>(combiner, mapper);
      }
  
      static final class FlatMapIntoIterable<T, U> implements Function<T, Publisher<U>> {
          private final Function<? super T, ? extends Iterable<? extends U>> mapper;
  
          FlatMapIntoIterable(Function<? super T, ? extends Iterable<? extends U>> mapper) {
              this.mapper = mapper;
          }
  
          @Override
          public Publisher<U> apply(T t) throws Exception {
              return new FlowableFromIterable<U>(ObjectHelper.requireNonNull(mapper.apply(t), "The mapper returned a null Iterable"));
          }
      }
  
      public static <T, U> Function<T, Publisher<U>> flatMapIntoIterable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
          return new FlatMapIntoIterable<T, U>(mapper);
      }
  
      public static <T> Callable<ConnectableFlowable<T>> replayCallable(final Flowable<T> parent) {
          return new ReplayCallable<T>(parent);
      }
  
      public static <T> Callable<ConnectableFlowable<T>> replayCallable(final Flowable<T> parent, final int bufferSize) {
          return new BufferedReplayCallable<T>(parent, bufferSize);
      }
  
      public static <T> Callable<ConnectableFlowable<T>> replayCallable(final Flowable<T> parent, final int bufferSize, final long time, final TimeUnit unit, final Scheduler scheduler) {
          return new BufferedTimedReplay<T>(parent, bufferSize, time, unit, scheduler);
      }
  
      public static <T> Callable<ConnectableFlowable<T>> replayCallable(final Flowable<T> parent, final long time, final TimeUnit unit, final Scheduler scheduler) {
          return new TimedReplay<T>(parent, time, unit, scheduler);
      }
  
      public static <T, R> Function<Flowable<T>, Publisher<R>> replayFunction(final Function<? super Flowable<T>, ? extends Publisher<R>> selector, final Scheduler scheduler) {
          return new ReplayFunction<T, R>(selector, scheduler);
      }
  
      public enum RequestMax implements Consumer<Subscription> {
          INSTANCE;
          @Override
          public void accept(Subscription t) throws Exception {
              t.request(Long.MAX_VALUE);
          }
      }
  
      static final class ZipIterableFunction<T, R>
      implements Function<List<Publisher<? extends T>>, Publisher<? extends R>> {
          private final Function<? super Object[], ? extends R> zipper;
  
          ZipIterableFunction(Function<? super Object[], ? extends R> zipper) {
              this.zipper = zipper;
          }
  
          @Override
          public Publisher<? extends R> apply(List<Publisher<? extends T>> list) {
              return Flowable.zipIterable(list, zipper, false, Flowable.bufferSize());
          }
      }
  
      public static <T, R> Function<List<Publisher<? extends T>>, Publisher<? extends R>> zipIterable(final Function<? super Object[], ? extends R> zipper) {
          return new ZipIterableFunction<T, R>(zipper);
      }
  
      static final class ReplayCallable<T> implements Callable<ConnectableFlowable<T>> {
          private final Flowable<T> parent;
  
          ReplayCallable(Flowable<T> parent) {
              this.parent = parent;
          }
  
          @Override
          public ConnectableFlowable<T> call() {
              return parent.replay();
          }
      }
  
      static final class BufferedReplayCallable<T> implements Callable<ConnectableFlowable<T>> {
          private final Flowable<T> parent;
          private final int bufferSize;
  
          BufferedReplayCallable(Flowable<T> parent, int bufferSize) {
              this.parent = parent;
              this.bufferSize = bufferSize;
          }
  
          @Override
          public ConnectableFlowable<T> call() {
              return parent.replay(bufferSize);
          }
      }
  
      static final class BufferedTimedReplay<T> implements Callable<ConnectableFlowable<T>> {
          private final Flowable<T> parent;
          private final int bufferSize;
          private final long time;
          private final TimeUnit unit;
          private final Scheduler scheduler;
  
          BufferedTimedReplay(Flowable<T> parent, int bufferSize, long time, TimeUnit unit, Scheduler scheduler) {
              this.parent = parent;
              this.bufferSize = bufferSize;
              this.time = time;
              this.unit = unit;
              this.scheduler = scheduler;
          }
  
          @Override
          public ConnectableFlowable<T> call() {
              return parent.replay(bufferSize, time, unit, scheduler);
          }
      }
  
      static final class TimedReplay<T> implements Callable<ConnectableFlowable<T>> {
          private final Flowable<T> parent;
          private final long time;
          private final TimeUnit unit;
          private final Scheduler scheduler;
  
          TimedReplay(Flowable<T> parent, long time, TimeUnit unit, Scheduler scheduler) {
              this.parent = parent;
              this.time = time;
              this.unit = unit;
              this.scheduler = scheduler;
          }
  
          @Override
          public ConnectableFlowable<T> call() {
              return parent.replay(time, unit, scheduler);
          }
      }
  
      static final class ReplayFunction<T, R> implements Function<Flowable<T>, Publisher<R>> {
          private final Function<? super Flowable<T>, ? extends Publisher<R>> selector;
          private final Scheduler scheduler;
  
          ReplayFunction(Function<? super Flowable<T>, ? extends Publisher<R>> selector, Scheduler scheduler) {
              this.selector = selector;
              this.scheduler = scheduler;
          }
  
          @Override
          public Publisher<R> apply(Flowable<T> t) throws Exception {
              Publisher<R> p = ObjectHelper.requireNonNull(selector.apply(t), "The selector returned a null Publisher");
              return Flowable.fromPublisher(p).observeOn(scheduler);
          }
      }
  }
  